pub fn dp_rec_mc(amount: u32) -> u32 {
    let denominations = [100, 50, 30, 20, 10, 5, 2, 1];
    let mut count = 0; // 记录纸币数量
    let mut remaining_amount = amount; // 剩余金额

    for &denomination in &denominations {
        // 用当前纸币面值尽可能多地找零
        count += remaining_amount / denomination; // 计算当前面值纸币的数量
        remaining_amount %= denomination; // 更新剩余金额

        // 如果剩余金额为0，提前结束
        if remaining_amount == 0 {
            break;
        }
    }

    count // 返回纸币的总数量
}
